Al-Qadi Abu Ya'la

Abū Yaʿlā Muḥammad ibn al-Ḥusayn Ibn al-Farrāʾ (April 990 - 15 August 1066), commonly known as al-Qāḍī Abū Yaʿlā, was a prominent Hanbali scholar and one of the early Muslim jurists who played dynamic roles in formulating a systematic legal framework and constitutional theory on Islamic system of government during the first half of the 5th/11th Century in Baghdad.

al-Qāḍī Abū Yaʿlā authored many works, including:

• Ṭabaqāt al-ḥanābila
• Kitāb al-muʿtamad fī uṣūl al-dīn
• al-Aḥkām al-sulṭāniyya
• Ibṭāl al-taʾwīlāt li-aḫbār al-ṣifāt
• al-ʿUdda fī uṣūl al-fiqh